the encyclopedic entry of Sciaridae

Dictionary Thesaurus Word Dynamo Quotes Reference Translator Spanish

Sciaridae

Sciaridae is a family of flies, commonly known as dark-winged fungus gnats. Commonly found in moist environments, they are known to be a pest of mushroom farms and are commonly found in household plant pots. This is one of the least studied of the large Diptera families, probably due to the small size of these insects and the difficulty in specific identification. There are currently around 1700 described species but there are estimated to be up to 20,000 species awaiting discovery, mainly in the tropics. More than 600 species are known from Europe.

Description

These gnats are small, from one to at the very most seven millimeters long. They have a slender, darkly colored body and dark wings. However, the females of several species are wingless. Their long legs and antennae with 8 to 16 segments are typical of many gnats.

Family Description (formal)

See

and images at Diptera.info

The slender whitish larvae feature a sclerotized head capsule.

Distribution

The Sciaridae occur worldwide, even in extreme habitats like antarctic islands and mountainous regions above 4,000 meters. Others (like Parapnyxia) are found in deserts, where they dig into the sand at extreme temperatures. Several species live exclusively in caves. However, most species live in forests, swamps, and moist meadows, where they live in the foliage. They are also often found in flowerpots. In moist and shadowy areas up to 70% of all diptera species can be Sciaridae.

They are distributed through wind and drifting, for example on dead wood, and are often introduced by humans, by means of transported humus or similar.

Species lists

Life cycle

The life cycle of only a few species has been studied in any detail, mainly those which are pests of commercially grown mushrooms. Sciarid larvae are mainly found in soil and plant litter where they seem to feed mainly on fungi and animal faeces. There are also species that mine in plant parts above and below the earth. The larvae play an important role in turning forest leaf litter into soil.

Adult females lay about 200 transparent eggs (each about one millimeter long) into moist soil. After about one week the larvae hatch. 90% of larvae are female. Up to 2,500 per m² can be found. Several species, especially Sciara militaris, can be found to migrate in processions of up to ten meters, containing thousands of individuals. These processions occur from May to June in central Europe. The larvae there pupate from July to August.

The adults with their characteristical dancing flight do not sting. They only ingest liquids and live only long enough to mate and produce eggs. They die after about five days.

The use of cedar wood chips is one way to keep Sciaridae away from plants.